Re: [PATCH] sfc: Fix reading non-legacy supported link modes

[Andrew Lunn]

On Tue, Oct 19, 2021 at 07:41:46PM +0200, Erik Ekman wrote:
> On Tue, 19 Oct 2021 at 17:21, Andrew Lunn <andrew@xxxxxxx> wrote:
> >
> > On Sun, Oct 17, 2021 at 07:16:57PM +0200, Erik Ekman wrote:
> > > Everything except the first 32 bits was lost when the pause flags were
> > > added. This makes the 50000baseCR2 mode flag (bit 34) not appear.
> > >
> > > I have tested this with a 10G card (SFN5122F-R7) by modifying it to
> > > return a non-legacy link mode (10000baseCR).
> >
> > Does this need a Fixes: tag? Should it be added to stable?
> >
> 
> The speed flags in use that can be lost are for 50G and 100G.
> The affected devices are ones based on the Solarflare EF100 networking
> IP in Xilinx FPGAs supporting 10/25/40/100-gigabit.
> I don't know how widespread these are, and if there might be enough
> users for adding this to stable.
> 
> The gsettings api code for sfc was added in 7cafe8f82438ced6d ("net:
> sfc: use new api ethtool_{get|set}_link_ksettings")
> and the bug was introduced then, but bits would only be lost after
> support for 25/50/100G was added in
> 5abb5e7f916ee8d2d ("sfc: add bits for 25/50/100G supported/advertised speeds").
> Not sure which of these should be used for a Fixes tag.

I would you this second one, since that is when it becomes visible to
users.

	Andrew